Williams Air Force Base

⚠ Superfund · Cleanup underway

Cleanup Status of Operable Units

Location

CityChandler
CountyMaricopa County
StateArizona
Coordinates33.30695, -111.65190

Contaminants of concern

Contaminated media

Cleanup timeline

  1. Initial Assessment Completed — 05/01/1985
  2. Proposed to the National Priorities List — 07/14/1989
  3. Finalized on the National Priorities List — 11/21/1989
  4. Remedial Investigation Started — 09/21/1990
  5. Remedy Selected — 12/30/1992
  6. Final Remedy Selected — 04/14/2000
  7. Remedial Action Started — 12/30/1992
  8. Final Remedial Action Started — 09/29/2014
  9. Construction Completed — Not Yet Achieved
  10. Deleted from National Priorities List — Not Yet Achieved

EPA references

Other Superfund sites in Maricopa County

EPA-regulated facilities nearby

Understanding this Superfund site

Williams Air Force Base is a federal Superfund site in Arizona. The Superfund program, created by Congress in 1980, addresses sites where hazardous substances have been released or threaten release into the environment. EPA scores potential sites using the Hazard Ranking System; those that score high enough are placed on the National Priorities List.

Current status: Cleanup underway. Active cleanup is underway, meaning EPA has approved a remediation plan and work is in progress. Cleanup timelines vary widely — some sites take decades depending on contamination depth, groundwater involvement, and funding availability.

EPA has identified 10 contaminants of concern at this site, including 1,4-dichlorobenzene, arsenic, benzene. Contamination has been detected in soil, groundwater, soil gas.

If you live near this site and have health concerns, your state health department can provide site-specific guidance. EPA maintains a community involvement program for most NPL sites, and site documents — including the Record of Decision, five-year reviews, and public health assessments — are typically available through EPA's Superfund site profile.